🛠 Repo: Update maintainers guide steps for releases

[JoshuaKGoldberg]

Tooling Suggestion Checklist

• I have tried restarting my IDE and the issue persists.
• I have pulled the latest main branch of the repository.
• I have read and agree to Mocha's Code of Conduct and Contributing Guidelines
• I have searched for related issues and issues with the faq label, but none matched my issue.
• I want to provide a PR to resolve this

Overview

#5159 -> #5186 automated our releases with release-please (heck yes!). We've got some old guidance in MAINTAINERS.md that no longer makes sense with our new flows:

mocha/MAINTAINERS.md

Line 378 in b6aa7e8

## Mocha's Release Process

Shall we update the maintenance docs? Now that much of it is automated, I bet it'll fix the fun long-standing note:

mocha/MAINTAINERS.md

Line 410 in b6aa7e8

_Note: there are too many steps above._

Additional Info

Related: #5345 -> #5363. I'd left a setting in the release-please config file that I shouldn't have.

This is particularly relevant to #5357. I'm not sure what steps to take for releasing Mocha 12.